Process for treating asphaltum to make varnish.



other similar solvents, leave on evaporation varnish, or other varnish.

UNITED STATES PATENT OFFICE.

DAVID T. DAY, OF WASHINGTON, DISTRICT OF COLUMBIA.

PROCESS FOR TREATING ASPHALTUM TO MAKE VARNISH.

967,337. No Drawing. Application filed April 18, 1906, Serial No.

To all whom it may concern:

Be it known that I, DAVID T. DAY, a citizen of the United States, residing at W'ashington, in the District of Columbia, have invented certain new and useful Improvements in Processes of Treatin Asphaltum to Make Varnish, of which t e following is a specification.

This invention relates to the process of treating various forms of asphaltum to obtain valuable products.

The object of my invention is to provide for obtaining from ground or liquid asphaltum certain elastic nitrogenous bodies, adapted to form, by the addition of a suitable solvent, an elastic varnish, which may be eflectively used as a substitute for shellac I have foundby experiment that when finely ground gilsonite,"or grahamite, or albertite, or other forms of ground or liquid asphaltum, or asphaltum from petroleum are carefully treated with nitric acid, the product is divided into a ortion heavier than water and a portion lighter than water. The portion heavier than water, after being suitably washed and dried and dissolved in alcohol, ether, benzol, benzin, or

of the solvent a very smooth, elastic varnish, adapted for use as a substitute for shellac varnish and other s irit varnishes.

Into a nitric aci bath is ently poured liquid, or finely ground aspha ltum, stirrin meanwhile, and the addition is continue so long as there is suflieient strength-left in the acid to attack the asphaltum. Care is taken to avoid a high elevation of temperature: this may safely rise to the boiling point of nitric acid, provided the acid be in excess. By this operation, part of the asphaltum is converted into nitroproducts which remain in solution in the acid while that part which is not converted remains on top of the acid and is drawn ofi therefrom for subse uent treatment. The acid containing in so ution the nitroproducts desired is poured into cold water and is so diluted as to cause it to deposit such nitro products. Most of the products so de osited sink to the bottom of the water, w 'le a part floats on the Water. The heavy por- Specification of Letters Patent.

Patented Aug. 16, 1910.

312,325. Renewed January 8, 1910. Serial No. 537,090.

tion, sinking to the bottom is then repeatedly washed with water until all trace of nitric acid is removed and theproduct is then dried in any well known manner. The dried product, thus obtained, may be dissolved in alcohol, ether, benzol, naphtha or other suitable solvent, thereby forming an elastic varnish suitable for immediate application.

In the above process that portion which floats on the top of the acid after the described treatment may be separately treated with nitric acid and the heavy portion dissolved in the acid treated as above described for the production of nitro-products. The nitro-products obtained are insoluble in water and are heavier than water.

By dissolving the dried nitro-products in one of the above mentioned solvents a ver smooth, elastic varnish is obtained, whicli is a suitable substitute for shellac varnish, or other spirit varnish.

Having described my invention, what I claim, and desire to secure by Letters Patent, is,--

1. The process of preparing nitroproducts from asphaltum which consists in mixing asphaltum with nitric acid, thereby making a nitroproduct solution of part of the asphaltum, drawing off the lighter undissolved portion, then diluting the nitroproduct solution with water, causing deposit of the resulting nitroproduct held in solution, then washin out the contained acid and drying the nitroproduct.

2. The process of reparing nitroproducts adapted for ma ing varnish, which consists 1n dissolving asphaltum in nitric acid, separatin the li ht surface oil trom the solution, d1 uting tie solution with water, thereby causing deposit of the contained nitroproducts, then washing to remove acid and dryin such products, then dis solving the drie product in a suitable solvent to make a varnish.

In testimon whereof I aflix my signature in presence 0 two witnesses.

DAVID 'r. DAY. [I.. 8. Witnesses:

ALTHA T. Coons,

Emzumrn A. BALLOOH. 

